1. Field of the Invention
This invention relates generally to windlasses and, more particularly to windlass pulleys for hauling either rope or chain.
2. Description of the Related Art
Pulleys capable of handling both rope and chain are often used in windlasses for hauling anchors. In one prior art rope/chain pulley disclosed in U.S. Pat. No. 3,792,622, an outer channel of pockets or ribs drives the chain while an inner groove or sheave arrangement drives the rope. When the chain is driven on one diameter of the pulley and the rope is driven on a distinctly different diameter, significant speed and torque variations between the chain and the rope result.
Some prior art pulleys, such as that disclosed in U.S. Pat. No. 4,034,556 have a number of tooth formations which serve to engage both rope and chain. The number of tooth formations is fixed by the pulley diameter and the size of the chain to be hauled. This design is satisfactory for hauling chain, however, slippage may occur when rope is engaged with the pulley. Rope slippage results from limiting the number of rope-driving teeth to the number of chain-driving teeth.